Radially clamping grips

ABSTRACT

A centrally apertured rotatable gripping device for radially clamping an axially moving object with a plurality of flexible filaments fastened therein, the device having an angular series of slots for restricting the movement of each flexible filament to a fixed radial direction.

United States Patent [54] RADIALLY CLAMPING GIIPS 5 Claims, 5 Drawing Figs.

(52 u.s.c| 51/59, 51/11.:

511 mm D01h7/00, nouns/o4 [50] Pick! of Search 57/34, 5!, 5L5. 59, 60, 77.3, 77.33, 77.4, 77.45, I06

[56] Relereaees Clted UNITED STATES PATENTS 733,299 7/l903 Sui 57/59 2,908.!32 l0/l959 Klemm 57/59X 3,270,49! 9/!966 DeLangen. 57177.45 3,372,537 3/l968 Poull et al... 57/59 3,408,807 1 H1968 Sylthe 57/59 Primary ExaminerDonald E. Watkins Attorneyr-lohn R. Bronaugh, George R. Powers and Floyd S.

Levison ABSTRACT: A centrally apertured rotatable gripping device for radially clamping an axially moving object with a plurality of flexible filaments fastened therein, the device having an angular series of slots for restricting the movement of each flexible filament to a fixed radial direction.

PATENTED JUN 8|97l 3 583 142 SHEET 1 OF 2 xxuixttv CLAMPING exits BACKGROUND This invention pertains to clamping grips of the class disclosed in US. Pat. No. 3,372,537 whereby an object, such as a yarn, is held angularly by flexible filaments which exert centripetal forces while permitting the object to move axially. Such clamping grips have proven particularly useful in textile machines for spinning and twisting yarn.

In the above-stated patent, a central opening contains a plurality of flexible filaments extending therethrough to form an axial passageway for the object to be gripped. Each filament has an arched portion and a straight portion, the arched portions, when combined, form a bow net of circular cross section and the straight portions lie parallel to each other in a bundle around the axis of the central opening. A sleeve of some deformable material may be placed around the bundle of filaments to increase the elastic and damping properties of the device. In certain instances it has been deemed desirable to omit the sleeve and depend entirely upon the flexible filaments to provide the forces to grip the object. Although the compressive force required to radially clamp the yarn is relatively slight, the force must be evenly applied to the periphery of the yarn.

When the yarn or other gripped object is of very small diameter, the filaments which furnish the clamping force must also be very small, as otherwise the space between the filaments would be too large for the yarn to be properly clamped. lfthe filaments are of fine gauge wire, a larger quantity is often necessary, with the disadvantage that the bundle may not open evenly to permit the yarn to pass through. The lower ends of the filaments in the bundle could migrate circumferentially from the fixed upper point and allow the compressive forces to dissipate. Under these conditions the flexible filaments form ing the bundle are not symmetrically distributed around the yarn and the combined clamping force may be insufficient for the purpose.

SUMMARY OF THE INVENTION This invention provides a simplified means for overcoming the above disadvantages. The gripping device includes a rotatable body having radially extending slots in each ofwhich at least one flexible filament is engaged so that each filament is restrained from movement except within the confines ofa particular slot.

It is the general object of the invention to devise a radially clamping grip in which a series of flexible filaments alone provide the clamping and damping forces necessary for gripping and axially moving articles of small diameter.

It is a further object of the invention to devise a radially clamping grip in which each one in a plurality of filaments is permitted flexing movement only within a particular radially extending plane.

It is a still further object to devise a clamping grip in which flexible filaments may be aligned radially in order to combine the centripetal force of two or more separate filaments.

These and other objects of this invention will become apparent as further details are disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described by reference to specific embodiments thereof as illustrated in the accompanying figures of drawing, wherein:

FIG. I is a view in longitudinal section of the invention,

FIG. 2 is a cross section taken on line ll-ll in FIG. 1,

FIG. 3 is a view in longitudinal section of a modification of the invention shown in FIG. 1,

FIG. 4 is a view in longitudinal section ofa variation of FIG. 3, and

FIG. 5 is a cross section taken on line V-V in FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Now referring to FIG. I, the clamping grip includes a body 1 having a head 2 with a hole 3 extending through both the body and head in an axial direction. The upper portion of the hole 3 terminates in a funnel 4 which forms the inlet of the clamping grip. Below the head 2 are several radially extending slots numbered 50 to 51 which extend downwardly through the remaining portion of the body I. I2 slots are shown in FIG. 2, however, the number may vary and, although shown as being equally spaced, some other symmetrical arrangement could be used. The slots lie in meridian planes which meet at the axis 6 of the hole 3 and they extend axially to the narrow end of the funnel 4.

A plurality of flexible filaments, 7a and 73 for example (FIG. I), each having an arched portion such as is shown by the numeral 8a, are distributed around the axis 6 so that the arched portion of each filament lies at least partially in a slot 5a5. For instance, the arched portion Ba of the flexible filament 7a lies in slot 5a. The end of the: arched portion of each flexible filament 7a7g etc. is embedded in a hole formed in the head 2, which holes are located in the planes of the slots 5a and SI. In FIG. 1 will be seen that the end of the arched portion 8a of the filament 7a is embedded in a hole located in the plane of slot 5a. Each flexible filament is so embedded, and together they form a clamping member, having a bow net generally designated 10 of circular cross section which encompasses the funnel 4, and a bundle II with the straight portions extending through the hole 3.

It will be seen that since every filament is at least partly inserted in a slot, it is guided thereby, so that when an object is engaged by the clamping grip, each filament will move away radially in a clearly defined plane which is the plane of the corresponding slot. Consequently, the flexible filaments stay uniformly distributed around the gripped object and the forces applied by the clamping member are uniformly distributed over the periphery of the gripped object.

In instances where the gripped object is very fine, such as a textile yarn, the flexible filaments must also be of very small diameter. It may be necessary to add to the resilient force applied by each filament to ensure that the object is properly gripped. The modification shown in FIG. 3 differs from FIG. 1 in that each slot contains two flexible filaments so that the resilient force applied in a given plane is the sum of the two forces exerted by the filaments in a particular slot. This is shown in FIG. 3 where flexible filaments Ma and 15a each have an arched portion 12a and 13a respectively and together, with a plurality of flexible filaments, they form two bow nets I6 and 17. The straight portions of the flexible filaments which extend from the two bow nets merge into a bundle 18.

To further increase the clamping force, more than two flexible filaments can be positioned in each slot. They can be distributed equally or arranged unevenly within the slots but in angular symmetry around the axis of the hole 3. This condition is shown in FIGS. 4 and 5 where every fourth slot, such as 20g, has three flexible filaments 21g, 22g and 23g and the intermediate slots, such as 200, have only two flexible filaments 21a and 22a. This distribution provides somewhat greater clamping force than the other two embodiments and the forces are distributed equiangularly about the gripped object.

This invention provides a clamping grip in which the forces exerted by all of the flexible filaments are directed in radial directions and the combined force can be increased by the application of other filaments in radial alignment within the slots.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

lclaim:

1. A rotatable gripping device for resiliently radially clamping an object while allowing axial sliding motion therethrough, said device comprising a. a body having a longitudinal through hole terminating in an inlet funnel,

of said flexible filaments by a portion of each said arched portion.

2. A gripping device as claimed in claim 1 wherein at least two said flexible filaments are engaged within each said slot, each said slot having an equal number offlexible filaments and the number of bow nets formed by the arched portions of said flexible filaments being equal to the number in each said slot.

3. A gripping device as defined in claim 1 wherein said flexible filaments are unequally distributed for engagement within said slots, the unequal distribution being arranged in angular symmetry about the axis of said body.

722 33 UNITED STATES PATENT OFFICE CERTIFICATE OF fiORRECTION Patent No. 3,583 142 Dated June 8, 1971 Inventor(s) CLAUDE GUIGNARD et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 19, change "5a-5" to 5a--51 Signed and sealed this 26th day of October 1 971 (SEAL) Attest= EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Acting Commissioner of Patents Attesting Officer 

1. A rotatable gripping device for resiliently radially clamping an object while allowing axial sliding motion therethrough, said device comprising a. a body having a longitudinal through hole terminating in an inlet funnel, b. a plurality of flexible filaments each having an arched portion and an extending straight portion, c. said flexible filaments being evenly distributed around the axis of said body so that the arched portions combine to form at least one bow-net, and the straight portions form a bundle, d. said body having the end of each said arched portion secured thereto and said straight portions disposed within said hole, e. said body having a plurality of radially extending slots beneath said inlet funnel, f. each one of said slots being adapted to engage at least one of said flexible filaments by a portion of each said arched portion.
 2. A gripping device as claimed in claim 1 wherein at least two said flexible filaments are engaged within each said slot, each said slot having an equal number of flexible filaments and the number of bow nets formed by the arched portions of said flexible filaments being equal to the number in each said slot.
 3. A gripping device as defined in claim 1 wherein said flexible filaments are unequally distributed for engagement within said slots, the unequal distribution being arranged in angular symmetry about the axis of said body. 